The convergence of the television and computer realms has been an important recent phenomenon. Although the convergence itself is now apparent, a number of unforeseen problems and opportunities have arisen as television sets have gained access to digital, computer-like resources integrated into the television itself or into an associated set-top box receiver. While some consumers already receive digital television broadcasts over proprietary cable and satellite networks, public wireless broadcasting has traditionally been analog. Public wireless broadcasts of digitized television signals has only recently begun in a very limited fashion in the United States.
Prior to the advent of wireless broadcast digital television, the consuming public primarily relied on analog television broadcast over spectrum allotted by the Federal Communications Commission (FCC) and transmitted in a manner defined under the National Television Standards Committee (NTSC) standard. NTSC television channels occupy 6 Megahertz slots in the electromagnetic spectrum and are defined in such a way as to control analog television sets in a raster scan method. The general nature of analog television signal broadcast and reception has not changed for decades, thus, for example, a well-made twenty year old television set may still receive and display signals as easily as it did when it was new.
Digital television broadcast and reception offers new challenges and opportunities. For example, multiple digitized television signals can now occupy a single 6 Megahertz slot, where only one analog channel previously existed. One way in which this has been done is to convert analog video signals into digital format for transmission. Straight analog-to-digital conversion of video signals results in very large amounts of digital data because video signals contain a large amount of information. For example, a single frame of digitized NTSC video may represent over 350 Kbytes of data. Since there are 30 frames/sec in standard videos, two hours of video, including the much smaller audio portion, is roughly equivalent to about 80 Gbytes. The data transfer rate would need to be 22 Mbytes/sec.
In order to reduce the data transfer requirements, digital video signals are oftentimes compressed before transmission and decompressed after reception by the set-top box or other digital broadcast receivers. The video signals may be compressed and decompressed by a variety of algorithms, including those defined in the Joint Photographic Experts Group (JPEG), Motion Pictures Expert Group (MPEG) 1, MPEG 2 and MPEG 4 standards.
The standards for compression and decompression continue to change. As new standards arrive, digital broadcast receivers designed under previous standards may not be compatible or may not be able to take full advantage of the capabilities available under a new standard. Many of the millions of set-top boxes that will soon be operating in the homes of millions of consumers may have all the necessary hardware and connections in place to operate under a new standard if they were provided with new software, but there is no convenient way to deliver the updated software to those set-top boxes. Methods such as transporting the set-top boxes to an authorized dealer are inconvenient, prohibitively expensive, and take too much time from many users' perspectives and therefore will fail to reach a large percentage of viewers. Furthermore, many users will have different set-top boxes or television receivers made with different software at different times by different manufacturers, which should all be updated as standards change.
Digital set-top boxes do not typically have an out-of-band channel that provides a mechanism to directly address and communicate with the set-top box. Implementing an out-of-band channel requires a land line, radio frequency modem, or the like, to connect to a private network server or an Internet server to receive updates as well as software to drive such a connection, all of which adds cost and complexity to the set-top box.
Although some of the problems with digital transmission have been described, there are opportunities as well. For example, ACTV, Inc. has described in various pending and issued patents the combination of broadcast television and Internet communications to improve the overall viewing experience and enable more focused advertising. As these and other applications are implemented, older set-top boxes may not have the software necessary to support this increased functionality.
What is needed is a way to remotely update digital set-top boxes in a public broadcast environment. What is also needed is a way to remotely update digital set-top boxes in a proprietary environment because digital set-top boxes in a proprietary environment, such as digital cable or direct broadcast satellite television, have many of the same issues as those in the public broadcast environment and require updated software for a variety of different set-top boxes.